Sains Malaysiana 35(2): 73-77 (2006)

 

 

Electrical Properties and Microstructure of Magnetoresistive

( (x = 0.0, 0.05, 0.15 and 0.3)

(Sifat Elektrik dan Mikrostruktur Bahan Magnetorintangan 

(x = 0.0, 0.05, 0.15 dan 0.3)

 

L.S. Ewe, N.A. Hamid

College of Engineering

Universiti Tenaga Nasional

43009 Kajang, Selangor, Malaysia

 

R. Abd-Shukor

School of Applied Physics

Universiti Kebangsaan Malaysia

43600 UKM Bangi, Selangor, Malaysia

 

 

ABSTRACT

 

The insulator-metal transition temperature, Tim of (x = 0.0, 0.05, 0.15 and 0.3) was studied during warming and cooling between 50 K to 300 K. The results showed that  Tim of  shifted to a higher temperature as Sr was substituted for La. Scanning electron micrographs showed that the average grain size is in the range of 0.6 µm - 1.4 µm. Grain boundaries are almost completely revealed for x = 0.3. X-Ray powder diffraction patterns showed cubic structure (space group Pm-3m) and contain no secondary phases.

 

Keywords:  magnetoresistance; microstructure; electrical resistance 

 

ABSTRAK

 

Suhu peralihan logam-penebat, Tim  (x = 0.0, 0.05, 0.15 and 0.3) telah dikaji bagi proses pemanasan dan penyejukan di antara suhu 50 K ke 300 K. Keputusan kajian menunjukkan suhu peralihan logam penebat  beralih ke suhu lebih tinggi apabila La digantikan dengan Sr. Mikrograf imbasan elektron menunjukkan butiran dengan purata saiz butiran di antara  0.6 µm - 1.4 µm. Sempadan butiran dapat dilihat bagi pendopan x = 0.3. Corak pembelauan sinaran-X menunjukkan struktur kubus (kumpulan ruang Pm-3m) tanpa fasa kedua.

 

Kata kunci: magnetorintangan; mikrostruktur; rintangan elektrik

 

 

REFERENCES

 

Es-Souni, M., Girdauskaite, E., Lakovlev, S., Solterbeck, C.H. & Zaporojtchenko, V. 2004. La0.8Sr0.2MnO3-d Heterostructure effects on the dielectric properties of PbTiO3-based thin films. Journal of Applied Physics 96(10): 5691-5696.

Grossin, D. & Noudem, J.G. 2004. Synthesis of fine La0.8Sr0.2MnO3 powder by different ways, Solid State Science 6: 939-944.

Hwang, Y.N., Cheong, S.-W., Radaeli, P.G., Marezio, M. & Batlogg, B. 1995. Lattice effect on the magnetoresistance in doped LaMnO3. Phys. Rev. Lett. 75(5): 914-917.

Jun Miao, Lixin Cao, Jie Yuan, Weiran Chen, Hao Yang, Bo Xu, Xianggang Qiu and Bairu Zhao. 2005. Microstructure dependence of the electrical properties of (Ba,Sr)TiO3 thin film deposited on (La,Sr)MnO3 conductive layer. Journal of Crystal Growth 276:  498-506.

Jung, J.H., Kim, K.H., Lee, H.J., Ahn, J.S., Hur, N.J. & Noh, T.W. 1999. Optical investigation of La7/8Sr1/8MnO3.  Phys. Rev. B 59(5): 3793- 3797.

Maurice, J.L., Pailloux, F., Barthelemy, A., Rocher, A., Durand, O., Lyonnet R. & Contour, J. P. 2002. Strain and magnetism in (La0.7Sr0.3)MnO3 very thin films epitaxially grown on SrTiO3. Applied Surface Science 188: 176-181.

McCormack, M., Jin, S., Tiefel, T.H., Fleming, R.M., Philips, J.M. & Ramesh, R. 1994. Very large magnetoresistance in perovskite-like La-Ca-Mn-O thin films. Appl. Phys. Lett. 64: 3045.

Urushibara, A., Moritomo, Y., Arima, T., Asamitsu, A., Kido, G. & Tokura, Y. 1995. Insulator-metal transition and giant magnetoresistance in La1-xSrxMnO3. Phys. Rev. B51(20): 14103-14109.

Yan Chunhua, Huang Yunhui, Wang Zheming, Zhang Lei, Gao Song, Liao Chunsheng and Xu Guangxian. 2000. Structural, magnetic and transport properties of Sc-doped La0.7Sr0.3MnO3. Chinese Science Bulletin 45(9): 810-813.

Yang, W.D., Huang, S.H. & Chang, Y.H. 2005. Microstructure, Magnetoresistance and electrical properties of La0.67Sr0.33MnO3 Film synthesized from citric acid and ethylene glycol. Thin Solid Films 478: 42-48.